Technical Field
The technology relates to an active vibration isolation system that uses feedback and feedforward control to reduce unwanted motion at a supported payload.
Discussion of the Related Art
Precision instruments that are used in various areas of technology (e.g., integrated circuit fabrication, metrology, various areas of microscopy, precision medical instruments etc.) benefit from isolation of ambient sources of noise that can couple unwanted motion (e.g., vibrations, impulses, etc.) into a precision instrument. In some cases, the instruments need to be vibrationally isolated to an extent where mechanical motions executed by an instrument are controllable to micrometer-scale dimensions or less in short periods of time, such as in optical steppers used for integrated circuit fabrication, atomic-force or optical microscopes, electron microscopes or electron-beam lithography tools, and read/write heads on memory devices. To achieve such performance, active vibration isolation systems may be employed between a precision instrument and a base which supports the instrument.